Sam McCullen studied at Cambridge School of Art, achieving a first class honours degree in Illustration and a Masters in Children's Book Illustration.
 
His first children's picture book, Billy Back-To-Front was published by Hodder Children's Books in 2006. Sam has also illustrated children's books by Julia Donaldson and Ian Whybrow.
 
He has received a number of awards, including a Highly Commended in the Macmillan Prize for Children's Picture Book Illustration, The Orchard Books Prize (for the most promising graduate for children’s book illustration 2003) and a Young Creatives’ Network Design & Communication Award.

In 2008, Sam was longlisted for The Big Picture Best New Illustrators Award.